If it has anything to do with a car, it can be found at the Specialty Equipment Market Assn., better known as SEMA, trade show. With more than 2,250 exhibitors in attendance this year, it is the largest show in SEMA's history. The show, which opened Tuesday and ends Friday, isn't open to the public. But it's no small affair. The event takes up 2.5 million square feet of space at the Las Vegas Convention Center -- and even spills out into the parking lot.